1. Field of Invention
This invention relates to a catalytic composition for coating the surfaces of cooking devices exposed to cooking residues thereby providing a porous film or surface containing catalytic materials which effect decomposition and oxidation of said residue. The invention is also directed to surfaces coated with the catalytic composition.
2. Prior Art
U.S. Pat. No. 3,266,477 issued to Stiles on Aug. 16, 1966 discloses use of oxidation catalysts in cooking devices to remove food and other cooking residues by catalytic oxidation. The patent teaches that use of the catalysts permits the cleaning of cooking devices at low oxidation temperatures so that the cooking devices are self-cleaning at temperatures of 204.degree. to 260.degree. C. (400.degree. to 500.degree. F.).
U.S. Pat. No. 3,271,322 issued to Stiles on Sept. 6, 1966 discloses a catalytic surface for cooking devices wherein the surface is composed of catalysts supported upon a particulate carrier which is anchored to a coating of polytetrafluoroethylene, said polytetrafluoroethylene being adhered to the surface of the cooking device.
U.S. Pat. No. 3,460,523 issued to Stiles et al. on Aug. 12, 1969 discloses a composition which is useful for coating the walls of cooking devices to provide a porous film containing catalytic materials. The composition contains at least 5% by weight on a dry basis of an alkaline silicate and at least 10% by weight of a thermally stable oxidation catalyst which is selected from the oxygencontaining compounds of zirconium, titanium, vanadium, chromium, manganese, cobalt, iron, nickel, tungsten, molybdenum, copper, zinc, the rare earths; the precious elements comprising rhenium, ruthenium, osmium, iridium, and platinum, and their mixtures. The patent teaches that the requisite oxidation catalyst should have a specific surface area of at least 0.1 square meter per gram. Coated surfaces made with those disclosed compositions are said to consist of a supported porous film having a porosity greater than 15% by volume.
In spite of the usefulness of the above-described compositions, there still exists a need for a catalytic coating composition which provides a catalytic surface effecting rapid disappearance of cooking residues at cooking temperatures of about 204.degree. C. (400.degree. F.) and below.